User interface for a portion of a display screen



FIG. 1 is a front view of a user interface for a portion of a display screen showing my new design; and,

FIG. 2 is a front view of a second embodiment.

The portions shown in broken line are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a user interface for a portion of a display screen, as shown and described. 